SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Rudolph Jacob T. (Last) (First) (Middle) 2500 TREX WAY C/O TREX COMPANY, INC. (Street) WINCHESTER VA 22601 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 02/21/2024	3. Issuer Name and Ticker or Trading Symbol TREX CO INC [ TREX ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) SVP, CHRO	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	43,439(1)	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Appreciation Right	02/15/2020(2)	02/15/2027	Common Stock	4,076	17.523	D
Stock Appreciation Right	02/14/2021(3)	02/14/2028	Common Stock	2,664	28.105	D
Stock Appreciation Right	02/13/2022(4)	02/13/2029	Common Stock	2,538	38.85	D
Stock Appreciation Right	02/19/2023(5)	02/19/2030	Common Stock	2,230	50.83	D
Stock Appreciation Right	02/17/2024(6)	02/17/2031	Common Stock	832	104.56	D
Stock Appreciation Right	03/01/2023(7)	02/23/2032	Common Stock	1,679	82.01	D
Stock Appreciation Right	03/01/2024(8)	02/14/2033	Common Stock	2,350	56.8	D
Stock Appreciation Right	03/01/2025(9)	02/19/2034	Common Stock	1,583	90.86	D

Explanation of Responses:

1. Includes 1,415 time-based restricted stock units that vest March 1, 2024; 2,023 time-based restricted stock units that vest March 1, 2025; 1,482 time-based restricted stock units that vest March 1, 2026; 607 time-based restricted stock units that vest March 1, 2027; a target number of 2,021 performance-based restricted stock units that vest on March 1, 2024; a target number of 2,889 performance-based restricted stock units that vest on March 1, 2025; a target number of 2,118 performance-based restricted stock units that vest on March 1, 2026; and a target number of 867 performance-based restricted stock units that vest on March 1, 2027. The number of performance-based restricted stock units set forth above is the target number of shares. The number of shares that will actually vest will be based upon performance against certain financial goals for the Company, and will range from 0% to 200% of the target number of shares.

2. This stock appreciation right became exercisable in three equal installments that occurred on February 15, 2018, February 15, 2019 and February 15, 2020.

3. This stock appreciation right became exercisable in three equal installments that occurred on February 14, 2019, February 14, 2020 and February 14, 2021.

4. This stock appreciation right became exercisable in three equal installments that occurred on February 13, 2020, February 13, 2021 and February 13, 2022.

5. This stock appreciation right became exercisable in three equal installments that occurred on February 19, 2021, February 19, 2022 and February 19, 2023.

6. This stock appreciation right became exercisable in three equal installments that occurred on February 17, 2022, February 17, 2023 and February 17, 2024.

7. This stock appreciation right became exercisable in three equal installments, the first installment became exercisable on March 1, 2023, the second installment becomes exercisable on March 1, 2024 and the third installment will become exercisable on March 1, 2025.

8. This stock appreciation right becomes exercisable in three equal installments occurring on March 1, 2024, March 1, 2025 and March 1, 2026.

9. This stock appreciation right becomes exercisable in three equal installments occurring March 1, 2025, March 1, 2026 and March 1, 2027.

	/s/ Amy M. Fernandez by power of attorney	03/01/2024
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
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